On-line oil injection lubrication system for small-caliber cold pipe blank unit

ABSTRACT

An on-line oil injection lubrication system of a small-caliber cold pipe blank unit comprises at least one intelligent oil supply assembly. The intelligent oil supply assembly comprises an upper industrial personal computer, a vector frequency converter and a hydraulic pump. The upper industrial personal computer adjusts the quantity of oil supplied by the hydraulic pump to the pipe blank inner hole oil injection assembly and/or the pipe blank outer surface oil injection assembly through the vector frequency converter. The on-line oil injection lubrication system can remarkably improve the quality of inner and outer surfaces of small-caliber stainless steel pipes and effectively solves various surface quality problems such as rolling burrs, rolling folds and micro-cracks caused by oil loss of the inner and outer surfaces of the small-caliber stainless steel pipes during the large-deformation rolling process.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation Application of PCT Application No. PCT/CN2021/111784 filed on Aug. 10, 2021, which claims the benefit of Chinese Patent Application No. 202021910167.9 filed on Sep. 4, 2020. All the above are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION 1. Technical Field

The invention relates to the field of metal forming equipment, in particular to an on-line oil injection lubrication system of a small-caliber cold pipe blank unit.

2. Description of Related Art

During the production process of seamless steel pipes, the inner and outer surface of small-caliber seamless steel pipes need to be lubricated online to reduce rolling friction, such that cracks and rolling burrs caused by excessive friction will not be formed on the inner and outer surfaces of pipe blanks. As the seamless steel pipes are rotated and fed in the rolling process and the speed is high, the lubrication of the seamless steel pipes must meet requirements, and rolling burrs will be generated in case of insufficient lubrication.

In the existing production process, real-time control cannot be realized merely by a flow control system according to the size, specification and material of pipe blanks, which has a great influence on the quality of pipes; in addition, because the technique of the control system is immature and the control precision is not high enough, the requirement for high-precision and high-speed control of liquid flow cannot be met. In view of this, an on-line oil injection lubrication intelligent control system of a small-caliber cold pipe blank unit is invented. The system can control lubricating oil injection in real time according to the size, specification and material of pipe blanks, such that the influence of friction between the inner surface of small-caliber seamless steel pipes and a mandrel and friction between the outer surface of the small-caliber seamless steel pipes and rollers is reduced, high-precision and high-speed effective control of liquid flow is realized, and the quality of pipes is improved; the system is of great significance in improving the production efficiency and can promote the networked and intelligent development of the production process.

BRIEF SUMMARY OF THE INVENTION

The technical issue mainly to be settled by the invention is to provide an on-line oil injection lubrication system of a small-caliber cold pipe blank unit, which can remarkably improve the quality of inner and outer surfaces of small-caliber stainless steel pipes, thus increasing the yield and effectively solving various surface quality problems such as rolling burrs, rolling folds and micro-cracks caused by oil loss of the inner and outer surfaces of the small-caliber stainless steel pipes during the large-deformation rolling process.

To settle the above technical issue, one technical solution adopted by the invention is as follows: an on-line oil injection lubrication system of a small-caliber cold pipe blank unit comprises a pipe blank inner hole oil injection assembly, a pipe blank outer surface oil injection assembly and at least one intelligent oil supply assembly, wherein the pipe blank inner hole oil injection assembly partially stretches into a pipe blank to inject oil into an inner hole of the pipe blank, a roller used for rolling the pipe blank is disposed on a front portion of the pipe blank, the pipe blank outer surface oil injection assembly is located outside the pipe blank and is used for injecting oil to a contact portion of the pipe blank and the roller, the pipe blank inner hole oil injection assembly comprises a mandrel rod and a mandrel, the mandrel is disposed in the inner hole of the pipe blank, the mandrel rod is connected to the mandrel, an oil passage is formed in the mandrel rod, an oil outlet part is disposed at an end of the mandrel, the oil passage is communicated with the oil outlet part, the pipe blank outer surface oil injection assembly comprises a support, an oil injection ring is movably mounted on the support, an oil injection channel is formed in the oil injection ring in an axial direction, multiple nozzles are connected to a front end of the oil injection channel, the intelligent oil supply assembly comprises an upper industrial personal computer, a vector frequency converter and a hydraulic pump, the hydraulic pump is connected to an oil tank, and the upper industrial personal computer adjusts the quantity of oil supplied by the hydraulic pump to the pipe blank inner hole oil injection assembly and/or the pipe blank outer surface oil injection assembly through the vector frequency converter.

In a preferred embodiment of the invention, the oil outlet part comprises multiple oil outlets which are obliquely arranged with respect to the axial direction, and exits of the oil outlets are located on the periphery of the mandrel.

In a preferred embodiment of the invention, the oil outlets are regularly arranged at intervals around the center of the mandrel, and the number of the oil outlets is three.

In a preferred embodiment of the invention, an oil injection cup is mounted at a left end of the mandrel rod, the oil injection cup is communicated with the oil passage and injects oil through the hydraulic pump, and a sealing shell is disposed outside the oil injection cup and is mounted in a pedestal.

In a preferred embodiment of the invention, the diameter of the mandrel gradually increases and then gradually decreases from left to right, and a top extension rod is connected to a right end of the mandrel.

In a preferred embodiment of the invention, the nozzles are arch flat nozzles, the number of the nozzles is three, and the nozzles are arranged close to each other and completely cover an outer side of the pipe blank.

In a preferred embodiment of the invention, the on-line oil injection lubrication system comprises one intelligent oil supply assembly which supplies oil to the pipe blank inner hole oil injection assembly and/or the pipe blank outer surface oil injection assembly synchronously; or, the on-line oil injection lubrication system comprises one intelligent oil supply assembly which supplies oil to the pipe blank inner hole oil injection assembly and the pipe blank outer surface oil injection assembly respectively.

In a preferred embodiment of the invention, the hydraulic pump delivers oil to the pipe blank inner hole oil injection assembly and the pipe blank outer surface oil injection assembly through an oil delivery pipe.

In a preferred embodiment of the invention, a pressure sensor used for detecting the internal pressure of the oil tank and a proximity switch used for detecting the liquid level in the oil tank are disposed in the oil tank.

The invention has the following beneficial effects: the on-line oil injection lubrication system of a small-caliber cold pipe blank unit can remarkably improve the quality of inner and outer surfaces of small-caliber stainless steel pipes, thus increasing the yield and effectively solving various surface quality problems such as rolling burrs, rolling folds and micro-cracks caused by oil loss of the inner and outer surfaces of the small-caliber stainless steel pipes during the large-deformation rolling process.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

To more clearly explain the technical solutions of the embodiments of the invention, drawings used for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are merely for some embodiments of the invention, and those ordinarily skilled in the art can obtained other drawings according to the following ones without creative labor. Wherein:

FIG. 1 is a structural view of a preferred embodiment of an on-line oil injection lubrication system of a small-caliber cold pipe blank unit of the invention;

FIG. 2 is a partial structural view of FIG. 1 ;

FIG. 3 is a partial structural view of FIG. 1 ;

FIG. 4 is a front view of FIG. 3 ;

Reference signs of components in the figures: 1, pipe blank inner hole oil injection assembly; 11, mandrel rod; 12, mandrel; 13, oil passage; 14, oil outlet part; 15, oil outlet; 16, oil injection cup; 17, sealing shell; 18, pedestal; 19, top extension rod; 2, pipe blank outer surface oil injection assembly; 21, support; 22, oil injection ring; 23, oil injection channel; 24, nozzle; 3, intelligent oil supply assembly; 31, upper industrial personal computer; 32, vector frequency converter; 33, hydraulic pump; 34, oil tank; 35, oil delivery pipe; 4, pipe blank; 5, roller.

DETAILED DESCRIPTION OF THE INVENTION

The technical solutions of the embodiments of the invention will be clearly and completely described below. Obviously, the following embodiments are merely illustrative ones, and are not all possible ones of the invention. All other embodiments obtained by those ordinarily skilled in the art based on the following ones without creative labor should fall within the protection scope of the invention.

Referring to FIG. 1 to FIG. 4 , an on-line oil injection lubrication system of a small-caliber cold pipe blank unit comprises a pipe blank inner hole oil injection assembly 1, a pipe blank outer surface oil injection assembly 2 and at least one intelligent oil supply assembly 3, wherein the pipe blank inner hole oil injection assembly 1 partially stretches into a pipe blank 4 to inject oil into an inner hole of the pipe blank 4, rollers 5 used for rolling the pipe blank are disposed on a front portion of the pipe blank 4, the pipe blank outer surface oil injection assembly 3 is located outside the pipe blank 4 and is used for injecting oil to contact portions of the pipe blank 4 and the rollers 5, the pipe blank inner hole oil injection assembly 1 comprises a mandrel rod 11 and a mandrel 12, the mandrel 12 is disposed in the inner hole of the pipe blank 4, the mandrel rod 11 is connected to the mandrel 12, an oil passage 13 is formed in the mandrel rod 11, an oil outlet part 14 is disposed at an end of the mandrel 12, the oil passage 13 is communicated with the oil outlet part 14, the pipe blank outer surface oil injection assembly 2 comprises a support 21, an oil injection ring 22 is movably mounted on the support 21, an oil injection channel 23 is formed in the oil injection ring 22 in an axial direction, multiple nozzles 24 are connected to a front end of the oil injection channel 23, the intelligent oil supply assembly 3 comprises an upper industrial personal computer 31, a vector frequency converter 32 and a hydraulic pump 33, the hydraulic pump is connected to an oil tank 34, and the upper industrial personal computer 31 adjusts the quantity of oil supplied by the hydraulic pump 33 to the pipe blank inner hole oil injection assembly 1 and/or the pipe blank outer surface oil injection assembly 2 through the vector frequency converter 32.

In addition, the oil outlet part 14 comprises multiple oil outlets 15 which are obliquely arranged with respect to the axial direction, and exits of the oil outlets 15 are located on the periphery of the mandrel 12. The oil outlets 15 are regularly arranged at intervals around the center of the mandrel 12, and the number of the oil outlets 15 is three.

In addition, an oil injection cup 16 is mounted at a left end of the mandrel rod 11, the oil injection cup 16 is communicated with the oil passage 13 and injects lubricating oil through the hydraulic pump 33, and a sealing shell 17 is disposed outside the oil injection cup 16 and is mounted in a pedestal 18. The diameter of the mandrel 12 gradually increases and then gradually decreases from left to right, and a top extension rod 19 is connected to a right end of the mandrel 12.

In addition, the nozzles 24 are arch flat nozzles, are arranged close to each other and completely cover an outer side of the pipe blank 4, the number of the nozzles 24 is six, and the nozzles 24 incline inwards by 6°-10° and can be adjusted to uniformly inject lubricating oil to the outer surface of the pipe blank in all directions to form a continuous circular oil film.

In addition, the on-line oil injection lubrication system comprises one intelligent oil supply assembly 3 which supplies oil to the pipe blank inner hole oil injection assembly 1 and/or the pipe blank outer surface oil injection assembly 2 synchronously; or, the on-line oil injection lubrication system comprises one intelligent oil supply assembly 3 which supplies oil to the pipe blank inner hole oil injection assembly 1 and the pipe blank outer surface oil injection assembly 2 respectively. The hydraulic pump 33 delivers oil to the pipe blank inner hole oil injection assembly 1 and the pipe blank outer surface oil injection assembly 2 through an oil delivery pipe 35. A pressure sensor used for detecting the internal pressure of the oil tank and a proximity switch used for detecting the liquid level in the oil tank are disposed in the oil tank 35. The vector frequency converter 32 is used to drive a motor and the hydraulic pump 66, the vector frequency converter directly controls the rotational speed of the motor and the oil pump to realize flow control of an oil circuit, and the system pressure is controlled by an overflow valve, such that the efficiency is improved and the cost is reduced under the premise of meeting process conditions. The upper industrial personal computer is completed off-line by means of a configuration and programming software package of a programmable logic controller (PLC) and is then downloaded to the controller as a complete file by means of a serial port of a computer, such that the functions such as voltage loss detection, flow control detection, and fault detection and alarm are realized. The system pressure can be guaranteed through a pressure actuator, and the system flow can be automatically controlled and adjusted according to changes of different specification class intervals. When the pipe blank is fed to the corresponding position, the proximity switch works, and the whole oil injection lubrication system can be automatically started and stopped according to the actual working condition; and the on-line oil injection lubrication system is connected to a cold pipe blank machine control system, so the main system can automatically control the branched lubrication system, a host computer can automatically lock the lubrication system and given alarm when the lubrication system breaks down, and the control completeness of the whole system is realized. The upper industrial personal computer and configuration software can comprehensively and dynamically display the dynamic flow in the operating and rolling process, and dynamic monitoring of the pressure loss and the multi-stage flow system, fault detection, alarm, fault diagnosis and system maintenance are realized.

The specific working principle of the on-line oil injection lubrication system of a small-caliber cold pipe blank unit is as follows: before rolling, the field staff operates the configuration software of the upper industrial personal computer according to different specification class intervals of pipes to adjust the power of the vector frequency converter so as to control the hydraulic pump to deliver oil; at this moment, a calculator in the industrial personal computer automatically calculates the oil injection quantity and speed required for rolling small-caliber seamless steel pipes with corresponding parameters and then transmits calculation results to the PLC, and the PLC controls the vector frequency converter to adjust the hydraulic pump to adjust the oil delivery speed.

The mandrel 12 is inserted into the inner hole of the pipe blank 4, the oil outlets 15 are located at the end of the pipe blank 4, and lubricating oil in the oil tank 34 enters the oil injection cup 16 through the oil passage 35 under the action of the hydraulic pump 33, and then flows out through the oil outlets 15 to be injected between the mandrel 12 and the pipe blank 4.

The oil injection ring 22 is disposed on the support 21, and the support 21 is fixed on a feeding side of a rolling mill; when a small-caliber stainless steel pipe is rolled, lubricating oil passes through the oil injection ring 22 and is uniformly injected to the outer surface of the pipe blank 4 in all directions through the arch flat nozzles 24, under the action of the hydraulic pump 33.

The upper industrial personal computer is completed off-line by means of a configuration and programming software package of a programmable logic controller (PLC) and is then downloaded to the controller as a complete file by means of a serial port of a computer, such that the functions such as voltage loss detection, flow control detection, and fault detection and alarm are realized. The system pressure can be guaranteed through a pressure actuator, and the system flow can be automatically controlled and adjusted according to changes of different specification class intervals. When a pipe blank is fed to the corresponding position, the proximity switch works, and the whole oil injection lubrication system can be automatically started and stopped according to the actual working condition; and the on-line oil injection lubrication system is connected to a cold pipe blank machine control system, so the main system can automatically control the branched lubrication system, a host computer can automatically lock the lubrication system and given alarm when the lubrication system breaks down, and the control completeness of the whole system is realized. The upper industrial personal computer and configuration software can comprehensively and dynamically display the dynamic flow in the operating and rolling process, and dynamic monitoring and control of a flow system are realized. The on-line oil injection lubrication system has the functions of fault detection, alarm and diagnosis and safety protection, and can realize remote monitoring, fault diagnosis, system maintenance, operation guidance and system upgrade through remote communication media.

Different from the prior art, the on-line oil injection lubrication system of a small-caliber cold pipe blank unit can realize on-line oil injection lubrication of the inner and outer surface of small-caliber stainless steel pipes and remarkably improves the quality of the inner and outer surface of the small-caliber stainless steel pipes, thus increasing the yield and effectively solving various surface quality problems such as rolling burrs, rolling folds and micro-cracks caused by oil loss of the inner and outer surfaces of the small-caliber stainless steel pipes during the large-deformation rolling process.

The above description is merely used for explaining the embodiments of the invention, and is not intended to limit the patent scope of the invention. All equivalent structures or equivalent flow transformations made according to the contents in this specification, or direct or indirect application to other related technical fields should also fall within the patent protection scope of the invention. 

What is claimed is:
 1. An on-line oil injection lubrication system of a small-caliber cold pipe blank unit, comprising a pipe blank inner hole oil injection assembly, a pipe blank outer surface oil injection assembly and at least one intelligent oil supply assembly, wherein the pipe blank inner hole oil injection assembly partially stretches into a pipe blank to inject oil into an inner hole of the pipe blank, a roller used for rolling the pipe blank is disposed on a front portion of the pipe blank, the pipe blank outer surface oil injection assembly is located outside the pipe blank and is used for injecting oil to a contact portion of the pipe blank and the roller, the pipe blank inner hole oil injection assembly comprises a mandrel rod and a mandrel, the mandrel is disposed in the inner hole of the pipe blank, the mandrel rod is connected to the mandrel, an oil passage is formed in the mandrel rod, an oil outlet part is disposed at an end of the mandrel, the oil passage is communicated with the oil outlet part, the pipe blank outer surface oil injection assembly comprises a support, an oil injection ring is movably mounted on the support, an oil injection channel is formed in the oil injection ring in an axial direction, multiple nozzles are connected to a front end of the oil injection channel, the intelligent oil supply assembly comprises an upper industrial personal computer, a vector frequency converter and a hydraulic pump, the hydraulic pump is connected to an oil tank, and the upper industrial personal computer adjusts the quantity of oil supplied by the hydraulic pump to the pipe blank inner hole oil injection assembly and/or the pipe blank outer surface oil injection assembly through the vector frequency converter.
 2. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 1, wherein the oil outlet part comprises multiple oil outlets which are obliquely arranged with respect to the axial direction, and exits of the oil outlets are located on a periphery of the mandrel.
 3. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 2, wherein the oil outlets are regularly arranged at intervals around a center of the mandrel, and the number of the oil outlets is three.
 4. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 3, wherein an oil injection cup is mounted at a left end of the mandrel rod, the oil injection cup is communicated with the oil passage and injects oil through the hydraulic pump, and a sealing shell is disposed outside the oil injection cup and is mounted in a pedestal.
 5. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 4, wherein a diameter of the mandrel gradually increases and then gradually decreases from left to right, and a top extension rod is connected to a right end of the mandrel.
 6. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 1, wherein the nozzles are arch flat nozzles, the number of the nozzles is three, and the nozzles are arranged close to each other and completely cover an outer side of the pipe blank.
 7. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 1, wherein the on-line oil injection lubrication system comprises one said intelligent oil supply assembly which supplies oil to the pipe blank inner hole oil injection assembly and/or the pipe blank outer surface oil injection assembly synchronously; or, the on-line oil injection lubrication system comprises one said intelligent oil supply assembly which supplies oil to the pipe blank inner hole oil injection assembly and the pipe blank outer surface oil injection assembly respectively.
 8. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 7, wherein the hydraulic pump delivers oil to the pipe blank inner hole oil injection assembly and the pipe blank outer surface oil injection assembly through an oil delivery pipe.
 9. The on-line oil injection lubrication system of a small-caliber cold pipe blank unit according to claim 8, wherein a pressure sensor used for detecting an internal pressure of the oil tank and a proximity switch used for detecting a liquid level in the oil tank are disposed in the oil tank. 